Electronic device



Nov. 21, 1939. H HOLLMANN 2,180,957

" ELECTRONIC DEYICE Filed April 14, 1937 INVENTOR HANS E HOLLMANN ATTORNEY Patented Nov. 21, 1939 STATES ATENT OFFICE I ELECTRONIC DEVICE tion of Germany Application April 14, 1937, Serial No. 136,745 In Germany April 6, 1936 11 Claims.

This invention relates to electronic devices and, in particular, to cathode ray tubes suitable for amplification and for oscillation generators. The invention in this application is an extension and improvement on my invention described in my copending application entitled Electronic system, filed February 24, 1937, and bearing Serial No. 127,343 wherein is described the method of producing displacement currents by electron beams. 30 In the above identified application there is described an arrangement for the amplification and production of undamped electromagnetic oscillations in which through an electrical or magnetic cross field a cathode ray performing transversal oscillations delivers its oscillation energy through influence to a' second cross field in the form of displacement currents.

By displacement current, of course, is meant those currents produced by mere displacement of 20 electrical charges from a normal position, without, however, actual transfer of the charge from one point in the circuit to another. This action, it will be readily recognized, is analogous to the action which takes place in the dielectric between 5 a pair of condenser plates in which the application of potential to the plates of the potential produces a displacement or electrical strain within the dielectric. Subsequent removal of this potential and short-circuiting of the plates will cause a current to How, which current results from the displacement of the electrons within the dielectric, corresponding, of course, to a displacement of charges.

In the above identified copending application, there is further described in particular a feed back arrangement in which, in place of the feed back channel formed by circuit elements, a second electron ray is used whose direction is opposite to that of the first one, and which permeates the two existing lateral fields in the direction opposite to that of the first ray. The two plate pairs of the lateral fields are connected to resonance systems, or perform as such parts of such systems and act at the same time as control means and as cross-control means for the two rays.

The distinction, therefore, between a displacement current and a convection or conduction current resides in the fact that in one case the electrons or charges are merely displaced, while in the convection current, the electrons are actually transported from one portion of the circuit to the other, and at the terminal point of the circuit surrenders the charge on the electrons. It will, therefore, be appreciated that in the case where a beam of electrons passes between two parallel electrodes and the beam is deflected in a plane perpendicular to the parallel electrodes, these lateral displacements of the beam from its normal position within the space enclosed by the elec- 5 trodes results in setting up a potential between the plates, and if the plates are suitably connected together, a current will fiow, which current is a displacement current.

It will be noted in this case that the current does not result from electrons impacting upon the parallel electrodes. It will thus be readily appreciated that since displacement currents depend upon the displacement of the charges, the current will be proportioned first to the magnitude of the charges, that is, the beam intensity, as Well as the rate at which the beam is displaced. This will probably become more clear in a consideration of the analogy of impressing A. C. voltage upon the plates of a condenser due to the 2 fact that the displacement current is a function of the rate of change of the displaced charge. It is well known that the current which flows through such a condenser is proportional to the frequency.

It will thus be appreciated that since the delivery of oscillation energy is not obtained by the impact of the beam of electrons upon one or several anodes as in the case of convection currents, but rather is dependent only upon the displacement of the charges, the space charge effect which is present in electron tubes making use of the convection currents, is of no effect where displacement currents are produced. Consequently, the steepness of the dynamic output current-control voltage characteristic increases with increasing frequency since the displacement current is proportional to the amplitude of the velocity of the electron charge moving between the deflection plates. 40

The subject matter of the present invention is to utilize the idea of using the same lateral field for one electron ray as control field and for another ray as cross-control field in a cascade amplifier arrangement. Hereby the advantage is obtained that for connecting successive amplifier stages no coupling lines and coupling elements are required, while the coupling is effected exclusively by means of electron rays which at the same time take care of the amplification of the oscillation amplitudes from one stage to the next one. The saving of coupling elements is of particular importance in case of highor ultra high frequencies whereby any connection line represents as such a considerable inductance.

To elucidate the idea of the invention as example of embodiment a three stage amplifier cascade is schematically shown in the figure. In the figure, I have shown one embodiment of my invention wherein a multiple set of deflecting plates and electron guns are used.

The cathode K1 together with an electronoptical system of reproduction A1 produce an electron ray E1 The latter passes through the control field P1 produced between the plates P1 and P1 by the alternating input potential 6e to be amplified, and carries out at this place transversal oscillations whose amplitudes increase with the increase in distance from P1. Now the ray passes through a second lateral field P2 between the plates P2 and P2" connected to each other across an inductive loop or Lecher wire system L2 which may be variable for the purpose of tuning, said plates forming an oscillatory system which can be tuned to the frequency to be amplified. The ray delivers the high-frequency contained in its transversal oscillations to this circuit through influence action and produces resonance potentials at the two plates P2 and P2" which are considerably amplified as compared with the originial control potentials es.

From the cathode K2 a second electron ray E2 departs across the reproducing system A2, and which moves opposite to the first ray, but inclined towards the latter by a small angle. The second ray likewise passes through the lateral field Pz. but hereafter it permeates a third cross field P3 likewise connected to a resonance circuit as in the case of P2. The resonance oscillations produced by the ray E1 between P2 and P2" subject the ray E2 to transversal oscillations and the latter delivers its high-frequency energy having been amplified for the second time as compared with the input potential Ce, to the oscillatory circuit P3-P3"La. In the same manner a third ray E3 is produced which again amplifies the resonance oscillations produced in P3L3 transmitting it to the cross field P4 from where they can be derived for any desired use, i. e., they may be applied for instance to a detector. For the sake of simplicity the arrangement according to the figure is such that the individual reproducing systems A for the preceding rays act respectively also as absorption electrodes but this may however also be carried out by special electrodes, Furthermore, instead of choosing individual rays in a position adjacent each other in the same plane, as is assumed in the figure for the sake of simplicity, they may also extend in a plane at right angles to the drawing plane in which case the deflection and decoupling plates can be spaced nearer each other.

The invention further permits of numerous modifications without departing from the basic idea of a cascade amplifier without coupling elements. Thus, the individual cross fields may be divided into several partial fields connected alternately in phase opposition so as to render their lengths independent of the time of passage of the electrons such as already proposed for increasing the sensitivity of oscillograph tubes at extremely high frequencies as shown and explained in my copending application. Furthermore, it is also possible to utilize the release of secondary electrons when the ray impinges on its absorption electrode and so forth for all subsequent rays, so that a single glow cathode is sufficient for the entire amplifier cascade. The other structure and the functioning of the individual stages correspond to the above identified copending application so that this feature does not require further elucidation. If inner feed backs are suppressed through shielding or completely symmetrical assembly or neutralization as shown for example in U. S. Patent No. 2,066,037 the travel time of the electrons from the control field to the delivery field plays no part in the cascade amplifier herein described.

Having described my invention, what I claim is:

1. The steps in the method of amplifying electrical signals which comprise producing a beam of electrons, deflecting the beam of electrons by the signals to be amplified, producing displacement currents by the deflected beam of electrons, producing a second beam of electrons, deflecting the second produced beam of electrons by the displacement currents, and producing displacement currents by the deflected second beam of electrons.

2. The steps in the method of amplifying electrical signals which comprise producing a beam of electrons, deflecting the beam of electrons by the signals to be amplified, producing displacement currents by the deflected beam of electrons, producing a second beam of electrons, deflecting the second produced beam of electrons by the displacement currents, producing displacement currents by the defiected second beam of electrons, producing a third beam of electrons, deflecting the third beam of electrons by the last named produced displacement currents, and producing displacement currents by the last named deflected beam of electrons.

3. The steps in the method of amplifying electrical signals which comprise producing a beam of electrons, deflecting the beam of electrons by the signals to be amplified, producing displacement currents by the deflected beam of electrons, producing a second beam of electrons, deflecting the second produced beam of electrons by the displacement currents, producing displacement currents by the deflected second beam of electrons, producing a third beam of electrons, deflecting the third beam of electrons by the last named produced displacement currents, producing displacement currents by the last named deflected beam of electrons, and supplying the last produced displacement currents to an. output circuite l. The method of amplifying an electrical signal which comprises the steps of producing a beam of electrons, producing displacement currents by the produced beam of electrons under the control of electrical signals to be amplified, and controlling a second beam of electrons by the produced displacement currents.

5. The steps in the method of amplifying electrical signals, which comprise the steps of producing displacement currents by an electrical signal controlled beam of electrons, and controlling a beam of electrons by the produced displacement currents.

6. An electronic amplifier comprising means for producing a beam of electrons, means for deflecting the beam of electrons by the signals to be amplified, means for producing displacement currents by the deflected beam of electrons, means for producing a second beam of electrons, means for deflecting the second produced beam of electrons by the displacement currents, and means for producing displacement currents by the deflected second beam of electrons.

7. An electronic amplifier comprising means for producing a beam of electrons, means for deflecting the beam of electrons by the signals to be amplified, means for producing displacement currents by the deflected beam of electrons, means for producing a second beam of electrons, means for deflecting the second produced beam of electrons by the displacement currents, means for producing displacement currents by the deflected second beam of electrons, means for producing a third beam of electrons, means for deflecting the third beam of electrons by the last named produced displacement currents, and means for producing displacement currents by the last named deflected beam of electrons.

8. An electronic amplifier comprising means for producing a beam of electrons, means for deflecting the beam of electrons by the signals to be amplified, means for producing displacement currents by the deflected beam of electrons, means for producing a second beam of electrons, means for deflecting the second produced beam of electrons by the displacement currents, means for producing displacement currents by the deflected second beam of electrons, means for producing a third beam of electrons, means for deflecting the third beam of electrons by the last named produced displacement currents, means for producing displacement currents by the last named deflected beam of electrons, and means for supplying the last produced displacement currents to an output circuit.

9. An electronic amplifier comprising means for producing a beam of electrons, means for producing displacement currents by the produced beam of electrons under the control of electrical signals to be amplified, and means for controlling a second beam of electrons by the produced displacement currents,

10. An electronic amplifier comprising means for producing displacement currents by an electrical signal controlled beam ofelectrons, and means for controlling a beam of electrons by the produced displacement currents.

11. An electronic device comprising a plurality of electron beam producing means positioned Within an envelope, a plurality of similar means for producing displacement currents, means to direct a beam of electrons from one of said plurality of beam producing means through one of said plurality of displacement current means, said one of said displacement current means simultaneously controlling another beam of electrons from a different one of said plurality of beam producing means, means to control the first named beam of electrons, and means to impact a beam of electrons from a third of said plurality of beam producing means upon a target electrode, including one of said means for producing displacement currents to control said last named beam of electrons by said second named beam of electrons.

HANS E. HOILMANN. 

